1. Field of Invention
The present invention relates to collection bags in appliances, such as a vacuum cleaner.
2. Description of Related Art
A variety of vacuum cleaners are presently available that collect dirt in a disposable paper bag filter. These vacuum cleaners are found in several forms including upright, canister, and wet/dry vac configurations. These device are sold under the brand names Hoover, Eureka, Royal Dirt Devil, Panasonic, Sanyo, Sears Kenmore, SHOP-VAC, Sears Craftsman, Ridgid, Genie, etc.
The majority of vacuum cleaners purchased today utilize a porous paper bag to filter and store dust collected by a vacuum cleaner. As air pneumatically conveys dirt into the bag, it exits through the porous paper media surrounding the cavity leaving the large dirt in the bag. Because of the relatively poor filtration efficiency of paper filter media, better vacuum cleaners employ multi-stage filtration systems that generally employ a HEPA backup filter to capture fine dust that penetrates through the paper bag filter. Lower-end vacuum cleaners have no backup filter and since consumers cannot retrofit their vacuum cleaner with a backup filter, they must suffer with dust emissions from their vacuum cleaners. Vacuum cleaners employing paper bag filters without backup filters provide such poor filtration that fine dust can be visually found accumulating on the inside of the vacuum cleaner housing that encompasses the paper bag filter. These dust emissions can also reduce the vacuum cleaner""s life by contaminating the motor in the suction device.
The filtration efficiency of a paper vacuum cleaner bag of the prior art is also reduced due to the design of the bag. In most paper vacuum cleaner bags the dirt enters the bag inlet at a high velocity and the dirt impacts the opposite wall of the bag. Thus the high velocity dirt particles penetrate the porous paper media resulting in low filtration efficiency.
Generally, paper bag filters need replacement monthly and HEPA filters require replacement annually. Over the life of the vacuum cleaner, the cost of replacement filters is often greater than the original cost of the original vacuum cleaner. In addition, it is of great inconvenience to the consumer to shop around locating the proper size vacuum cleaner bag to fit their vacuum cleaner. Moreover, disposable paper bag filters put unnecessary waste in our environment.
Because paper filter media is very porous, fine dust is traveling at a high velocity and it has a tendency of becoming trapped in the pores of the paper bag. Therefore the paper bag filter loses its permeability. As a consequence, the paper bag filters have limited reusability. In fact, it is well known that vacuum cleaners lose their ability to clean and pick up dirt as the paper bag is filled. This is because the partially clogged paper media restricts the airflow through the vacuum cleaner preventing it from collecting dust deeply embedded in carpet fibers. Therefore, most paper vacuum cleaner bag filters sold today are sealed shut so that the contents cannot be emptied and the bag reused.
U.S. Pat. No. 6,007,594 to Kaczor (1999) shows a multiple use vacuum cleaner bag which is of paper media construction thus offering poor filtration performance and limited reusability since the paper media clogs with particulate with use and it cannot be washed.
Vacuum cleaner bags of the prior art sometimes have electrostatically charged media lining the inside of the paper bag or consist of one thick layer of electrostatic media to improve the filtration efficiency of the bag. Typically, these type bags increase the filtration efficiency but not to the level of a HEPA filter. This improvement in filtration efficiency, however, decreases with time as the electrostatically charged sites on the media, which capture fine dust particles, become covered with dust and lose their ability to attract dust. Furthermore, these bags become clogged and manufacturers recommend that they be replaced when full.
Paper vacuum cleaner bags and the like are opaque and therefore the contents of the bag cannot be visually inspected. Consumers also have a tendency to overfill their paper bag filters. They either forget to check their bag filter""s contents because they cannot see through the opaque paper or they intentionally try to fill it completely to save money on purchasing replacement bags. This not only adversely affects the ability of the vacuum cleaner to clean, but it also frequently causes the bags to burst. Storing dust in vacuum cleaner bags between uses also has a tendency to develop strong odors. These offensive odors are most noticeable when the vacuum cleaner is first turned on.
In cases of wet/dry vacs used in construction, heavy materials such as cement and plaster dust can cause paper bags to rip when lifted out of the vacuum cleaner. In addition, sharp objects like nails, broken glass, wood chips etc. can cause paper bags to rip while in use. Furthermore, paper bags deteriorate and normally rip when liquids are collected.
As mentioned earlier, the poor filtration characteristics of paper bag filters is generally compensated for by creating multistage filtration systems comprised of a porous bag filter followed up by a backup or series of backup filters. The prior art, for instance, employs one of or a combination of electrostatic, non-woven or microfiberglass filters as a backup filtration system. These multistage filtration systems add significant cost and complexity to a vacuum cleaner.
In order to deliver high filtration efficiency, vacuums featuring multistage filtration systems require additional mechanical seals between each filtration stage to ensure all the air flowing through the vacuum cleaner is filtered and that no air bypasses the filters. Moreover, the chambers that house each filtration stage must be sealed to avoid leakage of dust through cracks in the vacuum cleaner housing. These additional seals add cost to manufacturing a vacuum cleaner and are the potential source of failure in-use from gasket damage, dry rot, and so on. Upon failure, these leaking joints in the vacuum cleaner not only can cause dust leaks into the surrounding environment but they can also decrease the suction of a vacuum cleaner and its ability to clean debris located deep down in carpet fibers.
Vacuum cleaner bags cannot be manufactured from commonly used high efficiency filter medias. If, for example, vacuum cleaner bags were manufactured from microfiberglass like most vacuum cleaners HEPA filters, the bags would be too brittle. Upon normal handling and usage the fibers would break and cause leakage of dust particles. Therefore hazardous materials such as medical waste or carcinogens cannot be contained in the bag for safe disposal and without contaminating the vacuum cleaner.
Vacuum cleaner bags also cannot be easily manufactured from expanded polytetrafluoroethylene (PTFE) membrane in current bag designs because current vacuum cleaner bag designs physically limit the amount of filtration media that can be used to that which is required to form a bag. This makes it difficult to adjust the amount of media to compensate for using less permeable, high efficiency media.
Many consumers already own vacuum cleaners that perform well with the exceptions of needing replacement vacuum cleaner bags and having low filtration efficiency. And there are consumers that have a genuine need to improve the filtration efficiency of their vacuum cleaner for health reasons and cannot afford the high-end vacuum cleaners that come equipped with HEPA filters. These consumers have no attractive method to retrofit their vacuum cleaner with an economical high efficiency vacuum cleaner bag.
The present invention addresses the aforementioned limitations of the prior art by providing a high efficiency vacuum cleaner bag fabricated of durable impermeable media having an air-permeable particle separator and inlet: that can eliminate the need for backup filters and complicated seals between filtration stages, that is suitable for new vacuum cleaners as well as retrofitting existing vacuum cleaners; that can have a re-sealable vacuum cleaner bag opening for dumping contents of bag so that it may be reused; that offers an improved design that reduces incoming dirt velocity to improve filtration performance, that can feature an antimicrobial treatment, scenting and absorbent filter to reduce odors being emitted.
Accordingly, it is an object of the present invention to provide an improved vacuum cleaner bag and method of operation for a vacuum system such as a vacuum cleaner.
It is another object of the present invention to provide a vacuum cleaner bag to retrofit existing vacuum cleaners with a high efficiency filtration system.
Yet another object of the present invention is to reduce the cost of operating a vacuum cleaner by providing an effective reusable vacuum cleaner bag.
A further object of the present invention is to eliminate the need for costly backup filters and the seals between each filtration stage by providing a high efficiency, single-stage vacuum cleaner bag.
An additional object of the present invention is to provide a superior vacuum cleaner bag design that reduces the velocity of the dirt entering the bag to improve filtration efficiency and life expectancy of a vacuum cleaner bag.
A significant object of the present invention is to contain hazardous materials completely in the bag for safe disposal without operator exposure or vacuum cleaner contamination.
A still further object of the present invention is to provide a vacuum cleaner bag that solves the problem of odor in the vacuum cleaner.
It is another object of the present invention to provide a re-sealable vacuum cleaner bag open end.
Yet another object of the present invention is to provide a vacuum cleaner bag that has a translucent media for inspecting the contents of the bag so that it can be emptied at appropriate intervals to sustain peak performance and avoid overfilling.
It is one more object of the present invention to provide a durable bag construction that can collect sharp, heavy objects and liquids without breaking.
Still one more object of the present invention is to significantly reduce disposable, paper vacuum cleaner bag and back-up filter waste and bring a positive impact on the environment.
One more object of the present invention is to reduce the time consumers spend shopping for replacement vacuum cleaner bags.
Another object of the present invention is providing a method of collecting dirt in a vacuum cleaner wherein dirt is conveyed into a bag comprising durable impermeable media and dirt is retained in bag cavity by an air-permeable particle separator as clean air exits the bag.